The Lilliput effect in the aftermath of the end-Permian extinction event

2007 ◽  
Vol 252 (1-2) ◽  
pp. 132-144 ◽  
Author(s):  
Richard J. Twitchett
Keyword(s):  
Extinction Event ◽  
Permian Extinction

Permian Hyolithida from Australia: the last of the hyoliths?

2009 ◽  
Vol 83 (1) ◽  
pp. 147-152 ◽  
Author(s):  
John M. Malinky
Keyword(s):  
Population Size ◽  
Upper Permian ◽  
Late Paleozoic ◽  
Early Cambrian ◽  
Progressive Decline ◽  
Early Devonian ◽  
Extinction Event ◽  
Permian Extinction ◽  
Abundance And Diversity ◽  
Geologic Record

Class Hyolitha Marek, 1963 encompassing the Order Hyolithida Sysoev, 1957 (Early Cambrian to Upper Permian) and Order Orthothecida Marek, 1966 (Early Cambrian to Early Devonian) consists of a group of conical, calcareous-shelled invertebrates of controversial affinity. One opponent view holds that hyoliths may be reasonably accommodated under the Phylum Mollusca (Malinky and Yochelson, 2007 and references therein), whereas another supports separate phylum status under the name Hyolitha (Pojeta, 1987 and references therein). Hyolith abundance and diversity attain a maximum in the Cambrian, followed by a progressive decline up to their Permian extinction (Fisher, 1962; Wills, 1993). Their demise was part of the extinction event of the Late PermianlEarly Triassic. The cause(s) of this event remains controversial (Erwin et al., 2002), and no imprint remains in the geologic record of the specific circumstances surrounding the disappearance of the hyoliths, though it is highly probable that reduced population size was a contributing factor. Given the overall rarity of Late Paleozoic hyoliths, every occurrence is worthy of note to better understand patterns of hyolith diversity and abundance in the Late Paleozoic, the geographic and stratigraphic distribution of hyolith taxa and circumstances related to their extinction. The species from the Upper Permian described herein is among the youngest, if not the youngest, members of class Hyolitha.

End-Permian mass extinction of foraminifers in the Nanpanjiang basin, South China

2009 ◽  
Vol 83 (5) ◽  
pp. 718-738 ◽  
Author(s):  
Haijun Song ◽  
Jinnan Tong ◽  
Z. Q. Chen ◽  
Hao Yang ◽  
Yongbiao Wang
Keyword(s):  
New Species ◽  
Quantitative Analysis ◽  
South China ◽  
Contact Surface ◽  
Mass Extinction ◽  
Extinction Rates ◽  
Extinction Event ◽  
Permian Extinction ◽  
Permian Mass Extinction ◽  
A New Species

Newly obtained foraminifer faunas from the Permian-Triassic (P-Tr) transition at the Dajiang and Bianyang sections in the Nanpanjiang Basin, South China, comprise 61 species in 40 genera. They belong to thePalaeofusulina sinensisZone, the youngest Permian foraminifer zone in South China. Quantitative analysis reveals that the last occurrences of more than a half of species (28/54) fall into a 60-cm-interval at the uppermost Changhsingian skeletal packstone unit and thus calibrate the end-Permian extinction to the skeletal packstonecalcimicrobial framestone boundary. About 93% (54/58) of species of the latest Permian assemblage became extinct in the P-Tr crisis. Four major foraminiferal groups, the Miliolida, Fusulinida, Lagenida, and Textulariina, have extinction rates up to 100%, 96%, 92%, and 50%, respectively, and thus experienced selective extinctions. BothHemigordius longusand ?Globivalvulina bulloidestemporarily survived the end-Permian extinction event and extended into the earliest Triassic but became extinct soon after. The post-extinction foraminifer assemblage is characterized by the presence of both disaster taxa and Lazarus taxa. Foraminifer distribution near the P-Tr boundary also reveals that the irregular contact surface at the uppermost Permian may be created by a massive submarine dissolution event, which may be coeval with the end-Permian mass extinction. A new species,Rectostipulina hexamerata,is described here.

scholarly journals Echinoids from the Tesero Member (Werfen Formation) of the Dolomites (Italy): implications for extinction and survival of echinoids in the aftermath of the end-Permian mass extinction

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7361
Author(s):  
Jeffrey R. Thompson ◽  
Renato Posenato ◽  
David J. Bottjer ◽  
Elizabeth Petsios
Keyword(s):  
Mass Extinction ◽  
Sea Urchins ◽  
Northern Italy ◽  
Early Triassic ◽  
Crown Group ◽  
Stem Group ◽  
Extinction Event ◽  
Permian Extinction ◽  
Permian Mass Extinction ◽  
A New Species

The end-Permian mass extinction (∼252 Ma) was responsible for high rates of extinction and evolutionary bottlenecks in a number of animal groups. Echinoids, or sea urchins, were no exception, and the Permian to Triassic represents one of the most significant intervals of time in their macroevolutionary history. The extinction event was responsible for significant turnover, with the Permian–Triassic representing the transition from stem group echinoid-dominated faunas in the Palaeozoic to Mesozoic faunas dominated by crown group echinoids. This turnover is well-known, however, the environmental and taxonomic distribution of echinoids during the latest Permian and Early Triassic is not. Here we report on an echinoid fauna from the Tesero Member, Werfen Formation (latest Permian to Early Triassic) of the Dolomites (northern Italy). The fauna is largely known from disarticulated ossicles, but consists of both stem group taxa, and a new species of crown group echinoid,Eotiaris teseroensisn. sp. That these stem group echinoids were present in the Tesero Member indicates that stem group echinoids did not go extinct in the Dolomites coincident with the onset of extinction, further supporting other recent work indicating that stem group echinoids survived the end-Permian extinction. Furthermore, the presence ofEotiarisacross a number of differing palaeoenvironments in the Early Triassic may have had implications for the survival of cidaroid echinoids during the extinction event.

scholarly journals Decoupling of morphological disparity and taxonomic diversity during the end-Permian mass extinction

Paleobiology ◽  
2021 ◽  
pp. 1-16
Author(s):  
Junyu Wan ◽  
William J. Foster ◽  
Li Tian ◽  
Thomas L. Stubbs ◽  
Michael J. Benton ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Microbial Mats ◽  
Benthic Communities ◽  
Ecological Impact ◽  
Taxonomic Diversity ◽  
Morphological Disparity ◽  
Extinction Event ◽  
Permian Extinction ◽  
Permian Mass Extinction ◽  
Marine Platform

Abstract An increasing number of unexpectedly diverse benthic communities are being reported from microbially precipitated carbonate facies in shallow-marine platform settings after the end-Permian mass extinction. Ostracoda, which was one of the most diverse and abundant metazoan groups during this interval, recorded its greatest diversity and abundance associated with these facies. Previous studies, however, focused mainly on taxonomic diversity and, therefore, left room for discussion of paleoecological significance. Here, we apply a morphometric method (semilandmarks) to investigate morphological variance through time to better understand the ecological consequences of the end-Permian mass extinction and to examine the hypothesis that microbial mats played a key role in ostracod survival. Our results show that taxonomic diversity and morphological disparity were decoupled during the end-Permian extinction and that morphological disparity declined rapidly at the onset of the end-Permian extinction, even though the high diversity of ostracods initially survived in some places. The decoupled changes in taxonomic diversity and morphological disparity suggest that the latter is a more robust proxy for understanding the ecological impact of the extinction event, and the low morphological disparity of ostracod faunas is a consequence of sustained environmental stress or a delayed post-Permian radiation. Furthermore, the similar morphological disparity of ostracods between microbialite and non-microbialite facies indicates that microbial mats most likely represent a taphonomic window rather than a biological refuge during the end-Permian extinction interval.

How to kill (almost) all life: the end-Permian extinction event

2003 ◽  
Vol 18 (7) ◽  
pp. 358-365 ◽  
Author(s):  
Michael J. Benton ◽  
Richard J. Twitchett
Keyword(s):  
Extinction Event ◽  
Permian Extinction ◽  
Almost All

Rapid demise and recovery of plant ecosystems across the end-Permian extinction event

2010 ◽  
Vol 74 (3-4) ◽  
pp. 144-155 ◽  
Author(s):  
Peter A. Hochuli ◽  
Elke Hermann ◽  
Jorunn Os Vigran ◽  
Hugo Bucher ◽  
Helmut Weissert
Keyword(s):  
Extinction Event ◽  
Permian Extinction

scholarly journals The permian end catastrophe – an evidence for a broader phenomenon

2018 ◽  
pp. 1
Author(s):  
Sergio Meth
Keyword(s):  
Energy Source ◽  
Solar System ◽  
Huge Amount ◽  
Asteroid Impact ◽  
Extinction Event ◽  
Solar System Bodies ◽  
Permian Extinction

It is well known that about 250 million years ago a huge catastrophe took place in our planet, with effects so big that about 90 % of the species disappeared in the process including sea animals. This event is called “the Permian extinction”. Other effects are also apparently connected to this event. This kind of event would require an extremely huge amount of energy. Since there are no evidences for an asteroid impact, the energy source should be searched inside the planet. Most important, it should show an energy source capable of producing such huge phenomenon. The aim of this paper is to propose a model to explain this extinction event and to show that there are evidences that this is a phenomenon that apparently happened several times not only in our planet but also in other Solar System bodies.

Detecting changes in morphospace occupation patterns in the fossil record: characterization and analysis of measures of disparity

Paleobiology ◽  
2001 ◽  
Vol 27 (4) ◽  
pp. 695-715 ◽  
Author(s):  
Charles N. Ciampaglio ◽  
Matthieu Kemp ◽  
Daniel W. McShea
Keyword(s):  
Missing Data ◽  
Sample Size ◽  
Simulated Data ◽  
Morphological Characters ◽  
Principal Coordinate Analysis ◽  
Distance Measures ◽  
Size Number ◽  
Extinction Event ◽  
Permian Extinction ◽  
Extinction Events

Recently, there has been much interest in detecting and measuring patterns of change in disparity. Although most studies have used one or two measures of disparity to quantify and characterize the occupation of morphospace, multiple measures may be necessary to fully detect changes in patterns of morphospace occupation. Also, the ability to detect morphological trends and occupation patterns within morphospace depends on using the appropriate measure(s) of disparity. In this study, seven measures were used to determine and characterize sensitivity to sample size of the data, number of morphological characters, percentage of missing data, and changes in morphospace occupation pattern. These consist of five distance measures—sum of univariate variances, total range, mean distance, principal coordinate analysis volume, average pairwise dissimilarity—and two non-distance measures—participation ratio and number of unique pairwise character combinations. Evaluation of each measure with respect to sensitivity to sample size, number of morphological characters, and percentage of missing data was accomplished by using both simulated and Ordovician crinoid data. For simulated data, each measure of disparity was evaluated for its response to changes of morphospace occupation pattern, and with respect to simulated random and nonrandom extinction events. Changes in disparity were also measured within the Crinoidea across the Permian extinction event.Although all measures vary in sensitivity with respect to species sample size, number of morphological characters, and percentage of missing data, the non-distance measures overall produce the lowest estimates of variance (in bootstrap analyses). The non-distance measures appear to be relatively insensitive to changes in morphospace occupation pattern. All measures, except average pairwise dissimilarity, detect changes in occupation pattern in simulated nonrandom extinction events, but all measures, except number of unique pairwise character combinations and principal coordinate analysis volume, are relatively insensitive to changes in pattern in simulated random extinction events. The distance measures report similar changes in disparity over the Permian extinction event, whereas the non-distance measures differ. This study suggests that each measure of disparity is designed for different purposes, and that by using a combination of techniques a clearer picture of disparity should emerge.

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